Organisms are noticed primarily due to their ability to reproduce. The existence of a large number of reproducing individuals within a species makes them more observable. Reproduction ensures the persistence and visibility of a species over time.

Populations of organisms fill well-defined places, or niches, in the ecosystem, utilizing their ability to reproduce.

The inbuilt tendency for variation during reproduction serves as the basis for evolution. The subtle differences in the surviving cells, caused by variations in DNA copies, contribute to the diversity and adaptation of organisms over time.